Along with the development of science and technology, communications technologies bring a lot of conveniences to human's life. A transmission network is an important component part of the overall telecommunication network and the transmission network provides transmission channels and a transmission platform for services carried in the entire network. On the other hand, due to various subjective and objective reasons, the transmission network might be interrupted because of faults, thus affecting the normal operation of transmission services and further bringing inconveniences or losses to human's work life. Moreover, since the modem society more and more depends on communications, the losses due to the fault and interrupting in the transmission network are larger and larger. Estimating according to a research, it is assumed that an optical cable of a wavelength division multiplexing (WDM) system bearing 160×10 Gbit/s is cut off, then it will cause the loss of approximately 16 million equivalent speech paths; and the communication interrupt for one hour will make an insurance company loss 20 thousand dollars, make an airline company loss 2.5 million dollars and make an investment bank loss 6 million dollars. Thus it can be seen that, the survivability of a communication network is a critical factor to be considered in design. When the services in the transmission network are interrupted, in order to reduce losses, it is necessary to minimize service recovery time as much as possible.
For a ring protection network consisting of a plurality of nodes, service data are transmitted through working channels when the ring protection network works normally. When the optical fiber between two nodes in the ring protection network is broken accidently, these two nodes switch the services in the working channel to a protection channel, and other nodes in the ring protection network pass through the protection channel so as to recover the operation of the transmission services of that ring protection network. When there is more and more multiplex section and ring protection in the SDH device, the number of the pass-through nodes becomes larger and the time for passing through also becomes longer. In addition, when the rate of optical ports composing the ring protection network becomes higher, the number of the pass-through time slots is also larger, which also increases the time for passing through with no doubt. It can be seen that reducing the time for the nodes passing through is most critical for the fast recovery of the services in the ring protection network. In the prior art, during network protection switching, a control module sends a plurality of time slots to be passed through to a time slot configuration module once, and the time slot configuration module is used to configure the plurality of time slots to achieve the time slot pass-through. However, in the time slot configuration process, the time slot configuration module needs to search or traverse the plurality of time slots, which increases the system overhead and occupies relatively long time, thus increasing the protection switching time and making against the fast recovery of services in the ring protection network.
Content of the Invention
The present invention provides a simple and feasible method and apparatus for fast passing through services to solve a technical problem that the time for passing through time slots is longer when a ring protection network of a SDH device performs protection switching.
In order to solve the above-mentioned technical problem, the present invention provides a method for fast passing through services in a SDH device, and the method comprises:
a protection switching module compresses first pass-through time slots between adjacent protection ports to a second pass-through time slot;
when an action of pass-through is triggered, the protection switching module sending the second pass-through time slot to a time slot configuration module to parse, and the time slot configuration module sending a parsing result to a time slot register to perform a process of a time slot pass-through.
Furthermore, in the above-mentioned method, before compressing the first pass-through time slots between the adjacent protection ports, the method further comprises: the protection switching module searching the first pass-through time slots between the adjacent protection ports.
Furthermore, in the above-mentioned method, the step of the protection switching module compressing the first pass-through time slots between the adjacent protection ports to the second pass-through time slot specifically comprises:
when compressing the first pass-through time slots to the second pass-through time slot, taking an input position and an output position of the first one of the first pass-through time slots as an input position and an output position of the second pass-through time slot, resetting a cross level of the second pass-through time slot, and taking the number of the first pass-through time slots to-be-compressed as a cascade number of the second pass-through time slot.
Furthermore, in the above-mentioned method, the protection switching module sending the second pass-through time slot to the time slot configuration module to parse and the time slot configuration module sending the parsing result to the time slot register to perform the process of the time slot pass-through, specifically comprises:
when the action of pass-through is triggered, the protection switching module sending the second pass-through time slot to the time slot configuration module;
after the time slot configuration module receives the second pass-through time slot, the time slot configuration module determining that the second pass-through time slot is in a compression format, and parsing the first pass-through time slots according to the cascade number of the second pass-through time slot;
the time slot configuration module sending the parsed first pass-through time slots to the time slot register to perform the process of the time slot pass-through.
Furthermore, in the above-mentioned method, said triggering the action of pass-through is: pulling out an optical fiber, initiating a protection switching control command in background or having an optical fiber fault.
The present invention also provides an apparatus for fast passing through services in a SDH device, and the apparatus comprises:
a protection switching module, adapted to search first pass-through time slots between adjacent protection ports and compress the first pass-through time slots to a second pass-through time slot;
a time slot configuration module, connected to the protection switching module and adapted to parse the second pass-through time slot to acquire the first pass-through time slots; and
a time slot register, connected to the time slot configuration module and adapted to configure the second pass-through time slots parsed by the time slot configuration module, so as to fulfill a process of passing through services.
The protection switching module is further adapted to: when compressing the first pass-through time slots to the second pass-through time slot, take an input position and an output position of the first one of the first pass-through time slots as an input position and an output position of the second pass-through time slot, reset a cross level of the second pass-through time slot, and take the number of the first pass-through time slots to-be-compressed as a cascade number of the second pass-through time slot.
Said protection switching module is further adapted to, when the action of pass-through is triggered, send the second pass-through time slot to the time slot configuration module; and correspondingly, the time slot configuration module is further adapted to, after receiving the second pass-through time slot, determine that the second pass-through time slot is in a compression format, and parse the first pass-through time slots according to the cascade number of the second pass-through time slot, and send the parsed first pass-through time slots to the time slot register to perform the process of the time slot pass-through.
Said triggering the action of pass-through is: pulling out an optical fiber, initiating a protection switching control command in background or an optical fiber fault.
With the method and apparatus for fast passing through services in the SDH device in accordance with the present invention, a plurality of the first pass-through time slots between the protection ports are searched in advance and compressed to the second pass-through time slot. When the action of pass-through is triggered, it is not necessary to search or traverse the plurality of first pass-through time slots again, and the number of time slots of the second pass-through time slot acquired after the compression is relatively smaller, thus reducing the processing time of the passing through configuration largely, which benefits to fast completion of the protection switching and achieves the fast recovery of the ring protection network services.